1. Field of the Invention
This invention relates to polyurethanes. More particularly, it relates to polyurethanes having improved physical properties, and process for making the same.
2. Description of the Prior Art
It is well known that polyurethane foams and elastomers having load-bearing properties can be obtained polymer polyols, which are prepared in general by polymerization of one or more ethylenically unsaturated monomers (such as acrylonitrile and combination thereof with styrene) in situ in polyols and have polymer content of 20-30% by weight. A few documents disclose epoxy-containing polymer polyols having a polymer content of about 20% by weight, but polyurethanes prepared from them have physical properties not so good as those prepared from polymer polyols of acrylonitrile alone.